Designed for 250–500-ton inland transport vessels, 9–12-meter yachts, and passenger boats, the Yuchai YC4A Marine Auxiliary Engine provides stable and efficient auxiliary power for light to medium marine applications. By combining advanced electronic control with optimized combustion technology, it delivers dependable performance, low operating costs, and enhanced onboard safety, making it a practical choice for modern inland and near-shore vessels.

High Reliability

The cylinder block and cylinder head use high-strength alloy cast iron with reinforced design to ensure excellent structural durability. The engine adopts an integral crankshaft and undergoes in-depth reliability development and validation. As a result, the major overhaul interval exceeds 10,000 hours, supporting long-term stable operation under continuous marine working conditions.

Energy Saving

Advanced in-cylinder three-dimensional combustion CFD technology optimizes the combustion process and reduces energy loss. A high-pressure common rail system, high-performance combustion chamber, and optimized intake swirl work together to achieve more complete combustion. Consequently, fuel consumption performance is significantly better than that of domestic engines in the same power range. In addition, Yuchai’s proprietary piston ring sealing technology reduces lubricating oil consumption by more than 50% compared with similar domestic products.

Safe and Comfortable Operation

The engine is equipped with digital intelligent local and remote monitoring instruments, enabling real-time monitoring and protection of engine operation. An integrated cast iron freshwater-cooled exhaust manifold effectively lowers engine room temperature, improving operational safety and onboard comfort during long-term use.

Environmental Protection

Full electronic control technology enables the engine to comply with China Marine Stage II and IMO Tier I emission standards, supporting cleaner operation and reduced environmental impact.